Observation of an <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>a</mml:mi><mml:mn>0</mml:mn></mml:msub></mml:math>-like State with Mass of 1.817 GeV in the Study of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msubsup><mml:mrow><mml:mi>D</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msubsup><mml:mo stretchy="false">→</mml:mo><mml:msubsup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mi>S</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msubsup><mml:msup><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:msup><mml:mrow><mml:mi>π</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math> Decays
M. Ablikim, М. Н. Ачасов, P. Adlarson, M. Albrecht, R. Aliberti, A. Amoroso, M. R. An, Q. An, X. H. Bai, Y. Bai, O. Bakina, R. Baldini Ferroli, I. Balossino, Y. Ban, V. Batozskaya, D. Becker, K. Begzsuren, N. Berger, M. Bertani, D. Bettoni, F. Bianchi, J. Bloms, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Çetin, J. F. Chang, W. L. Chang, G. Chelkov, C. Chen, G. Chen, H. S. Chen, M. L. Chen, S. J. Chen, T. Chen, X. R. Chen, X. T. Chen, Y. B. Chen, Z. J. Chen, W. S. Cheng, G. Cibinetto, F. Cossio, J. J. Cui, H. L. Dai, J. P. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, Z. Y. Deng, A. Denig, I. Denysenko, M. Destefanis, F. De Mori, Y. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, S. X. Du, P. Egorov, Y. L. Fan, J. Fang, S. S. Fang, Y. Fang, R. Farinelli, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, K. Fischer, M. Fritsch, C. Fritzsch, C. D. Fu, He Gao, Yang Gao, Yang Gao, S. Garbolino, I. Garzia, P. Ge, Z. W. Ge, C. Geng, E. Gersabeck, A. Gilman, L. Gong, W. X. Gong, W. Gradl, M. Greco, L. M. Gu, M. H. Gu, Y. T. Gu, C. Y. Guan, A. Q. Guo, L. B. Guo
Abstract
Using ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data corresponding to an integrated luminosity of $6.32\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected at center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform the first amplitude analysis of the decay ${D}_{s}^{+}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{+}{\ensuremath{\pi}}^{0}$ and determine the relative branching fractions and phases for intermediate processes. We observe an ${a}_{0}$-like state with mass of 1.817 GeV in its decay to ${K}_{S}^{0}{K}^{+}$ for the first time. In addition, we measure the ratio ${\mathcal{B}[{D}_{s}^{+}\ensuremath{\rightarrow}{\overline{K}}^{*}(892{)}^{0}{K}^{+}]/\mathcal{B}[{D}_{s}^{+}\ensuremath{\rightarrow}{\overline{K}}^{0}{K}^{*}(892{)}^{+}]}$ to be ${2.35}_{\ensuremath{-}0.23\mathrm{stat}}^{+0.42}\ifmmode\pm\else\textpm\fi{}0.1{0}_{\mathrm{syst}}$. Finally, we provide a precision measurement of the absolute branching fraction $\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}{K}_{S}^{0}{K}^{+}{\ensuremath{\pi}}^{0})=(1.46\ifmmode\pm\else\textpm\fi{}0.0{6}_{\mathrm{stat}}\ifmmode\pm\else\textpm\fi{}0.0{5}_{\mathrm{syst}})%$.